The use of biometric techniques to identify and/or authenticate the identity of a user is increasing. Biometric techniques that are promoted for this use include voice, fingerprint, iris, vein pattern and other scans. Currently, the use of fingerprint sensors for capturing a fingerprint has shown to be specifically promising, for example due to its ease of integration with different types of electronic equipment, such as smartphones, tablets, wearables such as smart watches or any other type of electronic devices where personalized user interaction is advantageous.
Biometric systems applying fingerprint sensors for collecting biometric data relating to a user typically provide for collection of fingerprint information, and compare that information against a database of known fingerprints. For example, a set of known fingerprints for a user can be collected, and subsequently authorized by comparing fingerprint information for that user against known fingerprint information. This generally involves collecting fingerprints from the authorized user and enrolling those collected fingerprints in that database of known fingerprint information.
During a typical prior art enrollment process, the user is instructed to place his finger on or in the close vicinity of the fingerprint sensor for collection of a predetermined plurality of fingerprint images of the finger of the user, where the finger preferably is slightly repositioned for each of the acquired images. The user might be prompted to move around the finger either less or more between subsequent image captures.
The process of collecting fingerprints from an authorized user may in some situations be experienced as time consuming, specifically for a skilled user enrolling multiple fingers on multiple devices. An exemplary disclosure trying to overcome this problem is disclosed in WO2014004210. WO2014004210 specifically addresses issues in relation to explicit time spent by a user for enrolling a finger, by performing the enrollment process in the background. That is, a plurality of partial fingerprint images is over time acquired using a fingerprint sensor comprised with an electronic device, and subsequently combined for forming a fingerprint template.
Even though WO2014004210 shows an interesting approach to reducing the dedicated user time needed for enrolling a finger of a user, the solution proposed in WO2014004210 may in some situations introduce safety issues, since it may be problematic to ensure that the fingerprint sensor does not form the template based on multiple users or multiple fingers for the same user. Such a situation may for example occur in case the electronic device is used/shared by multiple users. Accordingly, there seems to be room for further improvement, both from a security and from a usability perspective, for allowing a possible reduction of dedicated user time needed for enrolling a finger.